Field of the Invention
The present invention relates to a wedge-type lamp bulb assembly having a wedge-type lamp bulb and a socket which removably holds the wedge-type lamp bulb.
Description of the Prior Art
The wedge-type lamp bulb comprises a bulb portion containing a filament, and a wedge-shaped base; namely, it is of such a structure as to be held directly in a socket without using any conventional round base. FIGS. 1 to 3 show one example of conventional single-filament wedge-type lamp bulb assembly. As seen, the wedge-type lamp bulb 1 comprises a glass bulb 1a in which argon gas is charged and also a filament 1c is disposed, and a wedge-shaped base 1b. The filament 1c is supported by two lead wires 1e and 1f led out from the bottom of the wedge-shaped base 1b, bent at this base bottom, extended and folded back along the opposite lateral sides of the base 1b. The led-out portions of the above-mentioned lead wires 1e and 1f passed hermetically through the wedge-shaped base 1b are U-shaped as viewed from the front, which is seen from FIG. 1, and also L-shaped as viewed from the lateral sides, which is shown in FIG. 2. For flexing the lead wire portions near the above-mentioned folded-back portions of the lead wires, the wedge-shaped base 1b has recesses 1i and 1j formed therein in places corresponding to the folded-back portions of the lead wires. For assembling this wedge-type lamp bulb 1 into the socket 300 in a conventional lamp bulb assembly, contact terminals 2 like a leaf spring (will be referred to simply as "terminals") attached in the socket 300 are generally slid on and into contact with the above-mentioned contact terminals 1e and 1f. Namely, when the portions of the lead wires 1e and 1f near the above-mentioned U-shaped portions are flexed into these recesses 1i and 1j, respectively, as forced by the terminals 2, the lead wires 1e and 1f are electrically connected to the terminals 2, respectively, and the wedge-type lamp bulb 1 is thus held. However, since the wedge-type lamp bulb 1 is removably held by only the terminals 2 in the socket 300 in the conventional lamp bulb assembly, the lamp bulb 1 is likely to deflect in the direction of arrow in FIG. 2 so that the filament 1c in the lamp bulb 1 is difficult to be securely positioned. Also, as the lamp bulb 1 deflects, the terminals 2 holding the lamp bulb 2 is likely to be flexed, causing the electrical connection between the lead wires and terminals to be astatic.